It is known to use a laser beam to sever hair as an alternative to an arrangement of mechanical blades. Hair exposed to a laser beam will absorb energy from the laser beam and the hair will either be severed by vaporisation or by laser induced optical breakdown and a resulting shockwave. The laser beam does not require a moving cutting part to be placed against the skin or hair and so the problem of cutting elements becoming blunt is eliminated.
It is known that laser beams can cause damage and irritation to the user if the high intensity laser beam contacts the skin. It is also known to deactivate the laser beam when the skin is too close to the laser beam to avoid such damage and irritation being caused. However, the closest shave is achieved by keeping the distance between the laser beam and the skin surface to a minimum. This results in the laser beam being deactivated frequently. Deactivation of the laser beam when the skin is in the vicinity of the laser beam also results in hairs not being cut. Therefore, the number of strokes it takes for a user to achieve the desired closeness is too large to be acceptable for a normal shaving ritual or the length of the user's stubble is too long.
Patent application WO 2014/139968 A1 discloses a device for cutting hair wherein a laser beam is used to sever hairs, the laser beam being parallel to and spaced from the skin. The device according to WO 2014/139968 A1 is provided with a laser positioning mechanism which is arranged such that, during use, a distance between the laser beam and the is changed to maintain a predetermined distance.